Multilevel Signal Analyzer Tool for Optical Communication System

This paper presents an educational software interface tool to analyze multilevel signal at the receiver of an optical communication system. This tool provides visualization in terms of eye-diagram and bit/symbol error rate along the symbol duration using Gaussian approximation method. Besides that, maximum Q-factors, minimum BER and corresponding threshold level are also displayed. This tool is developed using Matlab as an interface programming tool. The developed analyzer has been used to analyze 2, 4 and 8-PAM signal for an optical communication system. A commercial software known as OptiSystem™ has been used to develop and simulate the multilevel optical system. The performance of the develop analyzer has been validated with the build in analyzer of OptiSystem.DOI:http://dx.doi.org/10.11591/ijece.v2i4.146

Indoor Optical Wireless Receiver – Theory And Design

This paper presents a systematic approach to the design of receiver for indoor optical wireless communication. In particular, it is concerned with how one can properly chooses the front-end preamplifier and biasing circuitry for the photodetector. A comparison between differences types of amplifier, and bandwidth enhancement technique is also discussed. For most photodetector applications, large values of RL and CD would severely restrict bandwidth. It is shown that a proper front-end design incorporates a transimpedance preamplifier which tends to integrate the detector output. Such a design provides significant reduction in photodiode capacitance and increase bandwidth when compared to a design which does not integrate initially. Two novel techniques, using bandwidth adjustment for better service quality with a bootstrapped transimpedance amplifier and bootstrapped composite transimpedance amplifier is presented. A controllable capacitance is introduced at the output of the second stage of the amplifier. These technique permits a bandwidth adjustment from 52Hz to 233MHz for a capacitance range of 10uF to 1pF, while the composite amplifier bandwidth adjustment of the circuit can be controlled in the frequency range of 6MHz to 60MHz for a capacitance range of 50pF to 1nF

Development of optical signal regeneration technique using ultrascale field programming gate array

The optical signal regeneration is a demanding research area for long-haul optical communication systems. The existing optical signal regeneration techniques are not facilitating for low BER in real-time. In this paper, a new optical signal regeneration technique is developed that provides low BER in real-time for 10Gb/s optical  degraded signal for Differential Phase Shift Keying (DPSK) signal at different transmission distances between 50 km to 250 km. The developed optical signal regeneration technique has achieved a very low Bit Error Rate  (BER) of 10-13 at low received the power of -17 dBm averagely for DPSK signal at different transmission distances experimentally via UltraScale FPGA.Keywords: Bit Error Rate (BER); Differential Phase Shift Keying (DPSK) signal; Optical Signal Regeneration,  Field Programming Gate Array

Peak to average power ratio (PAPR) reduction technique in orthogonal frequency division multiplexing (OFDM) using block coding

Orthogonal Frequency Division Multiplexing (OFDM) signal is considered a good candidate for wireless systems because it offers diversity gain in frequency selective channels. As in other multicarrier schemes, however, OFDM suffers from high peak to average power ratio (PAPR). This is a major drawback of the scheme and ways of minimizing the PAPR have been researched. Block coding scheme is the technique to reduce the peak-to-average power ratio of OFDM signals and also to detect transmission errors. The reason is that in the time domain, a multicarrier signal is the sum of many narrowband signals. At some time instances, this sum is large and at other times is small, which means that the peak value of the signal is substantially larger than the average value. This high PAR is one of the most important implementation challenges that face OFDM, because it reduces the efficiency. The main purpose in this project, is to make a comparison over the PAPR reduction technique using block coding and without block coding. The capability of Block Coding scheme to reduce the Bit Error Rate (BER) in an OFDM system was also measured. The simulation developed in Matlab simulation environment

Thermal Efficient Design of Distributed MemorGenerator for Dual-port RAM Using Unidirectional High-performance IO Standard

he distributeddual-port RAM offersthe high-speed data rate transmission for differentmemory access modes such as: busy mode; interrupt mode; JTAG mode; maser mode; slave mode; and sleep mode, at high-frequency operation. The execution of these modes at high-frequency operation increases the on-chip temperature of distributeddual-port RAM. It might short the distribute dual-port RAM forever. Currently, differenttechniques have been reported, but significanton-chip temperature consumption is not reduced for distributeddual-port RAM. In this paper, the thermal-efficiendesign for disributed dual-port RAM was achieved using IO sandard technique. The distributeddual-port RAM was designed using differentIO standardssuch as; LVTTL IO standardand Mobile_DDR IO standard.It was determined that distributeddual-port RAM was operated at 625 MHz high-frequency operation for busy mode, interrupt mode, JTAG mode, mastermode, slave mode, and sleep mode using LVTTL IO standardand Mobile_DDR IO standard.It was observed that for busy mode 53%, for interrupt mode 61%, for JTAG mode 68%, for mastermode 62%, for slave mode 59%, and for sleep mode 76% temperature was reduced when distrbuted dual-port RAM was designed using Mobile_DDR IO stndard compared to LVTTL IO stndard. The designed distributd dual-port RAM using Mobile_DDR IO stndard offerd the thermal efficiendesign solution for differentmemory access modes at high-frequency data rate transmission that provided the low on-chip temperature consumption. The developed distibuted dual-port RAM will be helpful to produce green computing devices

Thermal Efficient Design of Distributed MemorGenerator for Dual-port RAM Using Unidirectional High-performance IO Standard

he distributeddual-port RAM offersthe high-speed data rate transmission for differentmemory access modes such as: busy mode; interrupt mode; JTAG mode; maser mode; slave mode; and sleep mode, at high-frequency operation. The execution of these modes at high-frequency operation increases the on-chip temperature of distributeddual-port RAM. It might short the distribute dual-port RAM forever. Currently, differenttechniques have been reported, but significanton-chip temperature consumption is not reduced for distributeddual-port RAM. In this paper, the thermal-efficiendesign for disributed dual-port RAM was achieved using IO sandard technique. The distributeddual-port RAM was designed using differentIO standardssuch as; LVTTL IO standardand Mobile_DDR IO standard.It was determined that distributeddual-port RAM was operated at 625 MHz high-frequency operation for busy mode, interrupt mode, JTAG mode, mastermode, slave mode, and sleep mode using LVTTL IO standardand Mobile_DDR IO standard.It was observed that for busy mode 53%, for interrupt mode 61%, for JTAG mode 68%, for mastermode 62%, for slave mode 59%, and for sleep mode 76% temperature was reduced when distrbuted dual-port RAM was designed using Mobile_DDR IO stndard compared to LVTTL IO stndard. The designed distributd dual-port RAM using Mobile_DDR IO stndard offerd the thermal efficiendesign solution for differentmemory access modes at high-frequency data rate transmission that provided the low on-chip temperature consumption. The developed distibuted dual-port RAM will be helpful to produce green computing devices